Wenger is thought to be in the market for a striker and has admitted that his club were monitoring Lewandowski's situation before it became clear he was set for Bayern.

"Yes we looked into Lewandowski but honestly he signed for Bayern one and a half years ago, everyone knows that," Wenger said. "They can only make it official now because he is in the last six months of his contract.

"We are like everyone, we look out there and see what is happening. If an opportunity turns up, you know as well that all the big players are at big clubs at the moment and they go for important targets. Unless you have a club in a desperate financial situation it will be difficult.

"If we find someone like [Serge] Gnabry at that age when no-one knows them, then maybe. But I just said many times we don't rule anything out."

With Lewandowski due to arrive in the summer, Bayern forward Mandzukic's future has been the subject of conjecture - and Wenger has suggested his side are keeping an eye on the Croatia international's future.

"Lewandowski is at Dortmund until the end of the season and they will not sell Mandzukic now - maybe at the end of the season," Wenger said.

On Sunday, though, Bayern CEO Karl-Heinz Rummenigge insisted Mandzukic is not for sale, while his agent has also stressed he is not looking to leave the club.